Lithium

Awesome job! Looks fantastic, shame there are no power gains there but still a very sweet project and it'd be nice to think you may have improved response etc, +1 for video clips so we can hear the goodness We learn nothing by doing the same thing all the time.

Not sure, they later backed it up with an 8.62 @ 173 though

6.99 @ 192.74mph!!

Full weight GTR? Stripped out? Full street tyres, drag radials, DOT tyres or full slicks? What kind of transmission? Depends on whether you are building a full on drag car or want to do it with a full street car.

Remember guys, he said he wants 250kw to start with - with the view that he will eventually rebuild the motor and squeeze more out of it in future. It seems to me that he's in exactly the same position as I was a few years ago - at which point I wanted to start with ~240kw (Dyno Dynamics style) and would shoot for 270-300kw (DD style) when I had rebuilt the motor later on. After a bit of pissing around and learning a bit from my own tuning exploits I ended up with an internally gated .82a/r GT3076R and went straight for 270-280ishkw (DD style) without opening the RB25. I don't see any point shooting for as low as 250kw with a stock RB25, to be honest. I did ~100,000km with near twice the stock power of mine and the motor still hasn't given me a problem. I reckon one of the best quality (without spending absolute top dollar, of course) possible 250-300kw setups for an RB25 would be a Forced Performance GT3076HTA on a 6boost manifold.

Seriously? I've seen and know people who have got awesome results with HX35s... from WAY back, if I could talk to the guy I was in 2006 I would tell myself that my initial preference of going an HX35 on an aftermarket manifold instead of the the internal gated stock mount GT3076R for slightly cheaper would have probably been the better way to go.

I quickly discovered a page or so back he hates one of the best engine makers in the world - based on that lot I'd not really expect him to have the kind of appreciation or understanding of optimising engine efficiency needed to treat as an authority on the topic.

It is an interesting result, falls over quite early for a cammed RB25 with a GT3076R though - wonder if there is a restriction somewhere or something. I would have expected a bit more, but I guess we have fairly few internally gated/stock manifold E85 results to work from.

No way on earth I'd put one on a well modded RB26+, not at all convinced by them - there are plenty of better proven options.

Fair enough, seeya.

Cheers, will tell the owner that... he gets a kick out of people being incredulous at the results A huge amount of work into it to get there - it goes a tad beyond exhaust intake and VTEC controller but no its not the car we're matching a turbo for so a bit OT, was pointing out these things can breathe something fierce if they want to.

Yep, around 9.5:1 compression - and yeah, they are very good motors and have epic potential. My flatmates Prelude makes in the area of 190fwkw, which would be respectable for a turbo 4cyl even

I'm not actually sure what you're saying by saying "Thats some jump", surely you aren't talking about an RB25 over an H22A? Yeah, I had thought about the whole TD05/20G idea as well and still think its well worth considering though mindful of the fact that 240kw @ wheels on an EVO is pushing the old TD05s quite hard while there is the possibility we could be looking at numbers in that range from the Honda and really keen on ideally not becoming knock limited - or at least minimally so.

Roy - cheers, thats the 20G with TD06 hotside - right? Thats one of the reasons I am pondering the full TD06SL2 20G, an 18G etc will make >230kw - but they may need the boost more. The Honda needs decent flow at lower boost, and they drive turbos reasonably well. If we went TD05 (or even 06) with an 18G compressor and found that it isn't flowing quite as much as we need then that would be quite a pain. If we go TD06SL2 20G its going to make the power the engine will want to make on 11-12psi as far as I can tell, but it will be less responsive than the 18G (esp. TD05 hotside one), which relatively speaking is probably less of a fail as I can't see the TD06SL2 being terribly laggy relative to rev range. The trick here is the current turbo on the car is a Chinese 700hp something or another, so anything compared to that is probably going to feel supercharged The other thing to remember is with a filthy Honda, with this car the party starts at around 5500rpm and redline on this fella is 8000rpm regardless of if or what turbo is on it. Appreciate any thoughts or experience that might help with this, as at the moment just trying to make the best educated guess.

Have thought about that too, but can't help but feel that there is a possibility the owner will want to charge for more boost at some point in the future. I tend to think of F20Bs and more so H22As as parallels of RB25s, which I'd probably not put a TD05 on either. I think in this case a little more lag and more than enough flow would be the preferred, but still pondering on it.

Thinking about it further, does any of the Kando/Mitsi peoples think a TD06SL2-18G with 8cm housing could even work well for this setup - this is on a 2litre VTEC Honda running ~11psi for anyone who missed the first post I made about this.

Yeah they are offering a 3071HTA rebuild at least, I haven't seen it in the normal advertised complete units though. The options of rebuilding an existing unit to GT2868HTA, GT3071HTA, GT3073HTA, GT3076HTA etc have existed for a while but its a bit nicer to have the GT3073HTA as a straight out choice from new. I have in my head that the balance of flow vs spool etc would be fairly optimal with the GT3073HTA - the GT3071HTA would probably be an awesome choice if you were just going stock manifolds etc though.

Ahh I mixed Jez and Status' post and thought the latest talk was about TD06 20G setups. I was thinking a 20G with 8cm housing, car is currently running some kind of Ebay GT3582R look alike turbo which is both very laggy and potentially a grenade. Really anything thats nicer to drive and going to be reliable would be good, obviously T3 flanged a must. I'm going to be tuning it on a Dynapack, so should be looking at easily >220kw on 11psi.

This is good timing, a decision I've been pondering fits well into this actually. I'm helping with a budget build of a turbo Honda running an F20B engine (basically destroked H22A, makes 147kw stock) which will be running ~11psi - I have been seriously considering recommending one of these turbos with an 8cm hotside for it. I know on an RB25 would better suit a larger housing given you'd be pumping more boost into etc, but what about a slightly smaller engine which flows similar to the RB25 but will be running lower boost - do you think in these circumstances the 8cm may be more suiteable? As normal, aims are for a reliable turbo which isn't too laggy and particularly in the case of a +T type build, keep intake temps and exhaust pressure nice and engine friendly.

Awesome, keen as to hear how that goes... Whats the rest of the setup?

I'm a little excited to have caught wind that ForcedPerformance are bringing out a GT3073HTA turbo - that could really mix things up something nicely As far as I can tell, its basically going to be the same housings as the current Garrett 56trim GT3076R/GTX3071R/GTX3076R range but with the same 73HTA compressor wheel as the FP Green HTAs which were proven to make near 450whp on pump gas EVOs, or over 500whp on E85. Forced Performance rate the comp wheel at around 55lb/min, so in a similar range to the GTX3071R and GT3076R but with an overall smaller/lighter compressor wheel... it should be a seriously responsive beast and in my eyes could be basically the perfect match match for a GT30 turbine that never existed. I wish these things existed when I was shopping for a bolt on turbo back in the day, have seen no results but its an experiment I would most definitely do if I hadn't already.

The GT3586HTAs have definitely made some insane power, and are my preference... though the GTX3582Rs aren't exactly shrinking violets. Garrett used slightly misleading naming on their Garrett GTX range, the GTX3582R for example has a 83mm exducer - or 85mm if you factor in the extended tips. The old GT3582R had a 61mm inducer, while the GTX3582R inducer is 62.5mm (bigger than PT6262) which is getting up there considering a GT4088R is 63.5mm! Its a substantial sized compressor they are using, it'd be really interesting to drive a GT3582R and GTX3582R car back to back to see the difference.

Not sure, would be interesting to see - I'd say it should have the advantage.

ITP Race cars tuned a Skyline with a stock RB25 running a PT6262 BB turbo and made >350kw @ wheels on 98 octane, looked really good but the impression I got from the dyno plot was that it was making full boost in the area of 5000-5500rpm.... fairly inline with the impression I've always had of the PT6262s, quite laggy but quite potent. Never seen a comparison, but I'd suggest that the HTA GT3582R would spool better and be more responsive than the GTX3582R but that GTX3582R would be capable of more power.

I don't recall, is this a 2.5, 2.6 or 3litre now?